Abstract:

Production efficiency can be developed using proper production scheduling and dispatching methods. Prioritization of every product and correctly timed lot release control in a dynamically changing production environment can be controlled by considering demand, lead time, yield, work-in-process amounts and distribution for every different product dynamically. The thesis was made for Murata Electronics Oy wafer manufacturing factory which manufactures silicon sensor elements with MEMS (Micro Electro Mechanical System) – production process. Murata’s products are accelerometers, gyroscopes, combined sensors and inclinometers.

The theoretical section of the thesis includes the technical structures and typical constraints of wafer manufacturing, most common dispatching approaches to the lot release control and to the lot dispatching. The practical section describes the current state of the company, used production dispatching methods and the problems in production control. The proposed dispatching models, the implementations of these proposed dispatching models and the results are introduced and finally the recommendations for future work are given. The study was accomplished by analyzing the theoretical sources and Murata’s production process as well as doing practical problem solving and testing.

The implementations which were done during the thesis improve flow accuracy, production management and fulfillment of the production goals. The prioritization for every product and correctly timed lot release control improve reliability of delivery, production self-control and shorten the lead times. In addition, when production control is based on the pull and the demand, the dynamically changing production process can be properly managed and different issues can be responded to more rapidly.

In this research the used performance indicators are lead time, WIP (work-in-process), inventory size in days and throughput. The results period does not include results from the implementation of a lot release tool. However, from the results can be seen correspondence between factors: throughput target, actual throughput, lead time, WIP and inventory level in days, which are achieved from prioritization implementations. The better correlation between these factors results in a more manageable production process. The prioritization tools and lot release tools have also found to be very helpful for operators, production control operators, production planning experts and production managers.Tuotannon tehokkuutta on mahdollista parantaa tuotannonohjauksellisin keinoin. Erien priorisointi työjonoissa ja oikea-aikainen erien aloittaminen dynaamisesti muuttuvassa tuotannossa on mahdollista hallita huomioimalla tuotannonohjauksessa kysyntä, läpimenoaika, saanto, keskeneräisen tuotannon määrä ja jakauma jokaisella tuotteella erikseen dynaamisesti. Työn kohteena on Murata Electronics Oy:n anturielementtivalmistus, joka valmistaa piipohjaisia anturielementtejä MEMS (Micro Electro Mechanical System) – valmistusprosesseilla. Muratan tuotteet ovat kiihtyvyys-, kallistus- ja kulmanopeusantureita.